Thermo-hydro-mechanical modeling of permanent deformation of frozen soils under freeze-thaw conditions in permafrost regions

ABSTRACT: Degradation poses significant challenges in permafrost regions, considering the hazards associated with excessive ground subsidence, structural and ground instability, and increased infrastructure maintenance costs. Geotechnical design practices require an enhanced understanding of the concurrent interactions governing permafrost behavior under freezing and thawing conditions. During freeze-thaw cycles in cold region soils, irreversible deformations accumulate, which are critical for evaluating the performance of structures in cold and permafrost regions. This study introduces a thermo-hydro-mechanical model to simulate the permanent deformation of permafrost by focusing on plastic deformation mechanisms. The formulation implemented using the Multiphysics Object Oriented Simulation Environment (MOOSE) employs a straightforward yet robust approach that is extendable to various constitutive models, enabling its application across a wide range of soil types and environmental conditions. By integrating a plastic constitutive model into the governing equations, the proposed model captures irreversible deformation during freeze-thaw conditions, addressing a key limitation in existing permafrost models. The results demonstrate the capability of the model to predict deformation patterns. Furthermore, insights into stress-strain behavior and the impact of temperature disruption on permafrost are demonstrated. The findings are intended to support geotechnical engineers and researchers in designing resilient infrastructure that can accommodate the unique challenges of permafrost degradation under a changing climate.